Automatic rhythm device



De@ 12, 1967 R. H. CAMPBELL, JR

AUTOMATIC RHYTHM DEVICE 2 Sheets-Sheet l Filed June 25, 1964 Dec. l2, 1967 R. H. CAMPBELL, JR

2 Sheets-Sheet 2 Filed June 26, 1964 INVENTOR.

RICHARD H. CAMPBELL,JR.

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NQ mm1 CCCCEICI$M United States Patent 3,358,068 AUTOMATIC RHYTHM DEVICE Richard H. Campbell, Jr., Gilford, N.H., assignor to The Seeburg Corporation, Chicago, Ill., a corporation of Delaware Filed June 26, 1964, Ser. No. 378,365 11 Claims. (Cl. 84-1.01)

ABSTRACT F THE DISCLOSURE A pulse generator drives a frequency dividing counter chain and the outputs of both are connected as inputs to a diode matrix such that the pulse outputs of the various counter stages appear on the output lines of the matrix. These output lines are AND and OR connected to produce a pulse train having any desired sequence combination of the pulse outputs of the counter stages to drive the rhythm instruments of an electronic organ. The frequency of the pulse generator is either manually or automatically controlled to set the tempo of the rhythm sounds produced by the organ.

This invention relates generally to an automatic repetitive rhythm instrument for use in association with a musical instrument in which various selectable rhythm sound combinations may be obtained with the sounds produced in tempo with the musical instrument and the selection being played.

This invention is an improvement over the arrangement disclosed and claimed in Rhythm Tempo Control System, Serial No. 217,713, 'and now Patent No. 3,217,307, the disclosure of which is hereby incorporated by reference for the detailed disclosure of various circuits for achieving rhythm sound patterns. Further details of the circuits herein disclosed are shown in applicants copending application, as co-inventor with Park, for Musical Instrument, Serial No. 378,364, iiled Iun'e 26, 1964.

The present invention provides an `all-electronic arrangement for achieving yrepetitive rhythm sound patterns, thereby providing economies of manufacture and greater versatility in formulating desired rhythm pulse combinations, and permitting a wide selection of rhythms and rhythm instrument sounds to be made available to the player of the instrument with a minimum of circuit cost and complexity.

In accordance with the present invention, an electronic pulse generator is provided which generates a pulse train which is a multiple of the basic rhythm frequency of the instrument. This pulse frequency is variable over a range which corresponds to the range over which the basic rhythm tempo varies for various types of musical compositions, and the variation in the frequency of the pulse generator is controlled by a frequency control input signal. The output of the pulse generator is applied to a counter to provide sub-division of the pulse generator frequency down to the basic rhythm frequency of the instrument, and the outputs from the various stages of the counter are applied to a matrix to gate the output of the pulse generator to a plurality of output lines, with the gating provided by the matrix being such that each output line has a predetermined combination of pulses thereon. These output lines may be combined in various arrangements through OR circuits or various AND circuit combinations to provide the more complex rhythm patterns which are required, and these output lines are then selectively connected to the various rhythm instruments so lCe that the pulse pattern is translated into a sound pattern providing the combination pulses reproduced as the various rhythm instruments.

When the rhythm instrument is used with or incorporated in an automatic or player-operated instrument such as an electronic organ, the output of the counter is also utilized to develop a polarized signal representative of the timing of the rhythm beat. By combining this polarized signal with the signal from the pedal keyboard of an electronic organ or similar signal from other player-operated instrument an error signal is developed which can be utilized as the frequency control input to the pulse generator. Thus the repetitive rhythm patterns are generated in tempo with the tempo of the composition being played on the complete instrument. As an alternative, the frequency control of the pulse generator can be manually selected at any desired frequency for the purposes of producing novelty etfects or Where the player of the player-operated instrument desires to follow a preset rhythm rather than have the rhythm instrument follow the tempo which the player imposes upon the instrument by manipulating the pedal keyboard.

Accordingly, the object of the present invention is to provide an improved all-electronic repetitive rhythm instrument for use with various musical instruments such as an electronic organ and capable of supplying a wide variety of rhythm sound combinations and tempos for accompanying such an instrument, either automatically or selectively adjustable.

The features and objects of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a block diagram of the system in accordance with the invention, and

FIG. 2 is a waveform diagram showing the relation of the pulse generator output and the outputs of the various stages of the counter.

Referring now to FIG. l, a pulse generator 11 is shown having a frequency control input 12. The pulse generator 11 may be any form of free-running oscillator circuit which provides a pulse output on line 13 within the range generally corresponding, for example, to twenty-four times the basic beat tempo that is imposed on the instrument by a player. The generator 11 is also adapted to be frequency controlled by an electrical input signal on line 12 and for this purpose may include voltage variable capacitors or variable reactance devices for producing the electrical frequency control in any manner known to the art.

The output pulse train on line 13 is applied to the input of a counter 14 which has as a rst stage 15 a scale-of-three stage followed by four binary stages 16, 17, 18, and 19. The output of the scale-of-three stage 15 has three states, and three output lines 21 from the scale-of-three counter 15 are energized in succession. These outputs 21 are designated 0, 1, and 2 to represent the three states of the scale-of-three counter 15. Each of the binary stages 16-19 has two outputs designated 0 and 1 in conventional fashion.

The outputs 21 of the scale-of-three stage 15 and the 0 and 1 outputs of the binary stages 16-19 supply and are connected to input lines 22 of an interconnection matrix 23 which may be wired in any desired interconnection combination of inputs and outputs hereinafter referred to as a matrix. The matrix 23 has a plurality of horizontal lines 24 and 24. The output 13 of pulse generator 11 is also connected as an AND E input to all of the output lines 24 and 24 by means of AND resistors 25 with the AND circuit completed by a pattern of diode connections between any input line 22 and any output line 24 or 24 as indicated by diodes 26. Thus an output line 24 or 24 will receive a pulse from pulse generator 11 only when that pulse is the one which occurs when the diodes connected thereto are enabled by the appropriate Voltage level onl the outputs of the various stages of the counter 14 to which the particular output line 24 0r 24 is connected by means of diodes 26. In the example shown, positive voltage logic is employed as indicated by the polarity of the AND and OR diodes. In this manner, various combinations of pulses can be obtained on the output lines 24 and 24. The output lines 24 are connected by means of conductors Z7 to various points on a selector switch assembly 28 by corresponding conductors 3).

The selector switch 28 can be any desired type such as that disclosed in the application Ser. No. 217,713. The output of the selector switch 28 supplies a plurality of rhythm instruments 29 which are, in turn, connected as input to an audio section 31. The audio section 31 may have a melody input 32 and an input from pedal keyboard 33 with all signals being combined to produce a composite output in the audio transducer system 34 where the complete melody and rhythm composition is rendered audible.

The selector switch 28 has an operative control 35 which permitsthe operator to select any desired rhythm sequence combination as shown hereinafter with reference to Table I. These pulse combination inputs are channeled by the selector switch 28 into the various rhythm instrument devices 29, which produce, for example, the sound of the snare drum, cymbal, blocks and any other desired rhythm sound in the cadence of the selector pulse combination derived from the lines 27 and selected by the selector switch 28 under the control of the player. The detailed arrangements for this selection and generation of the various rhythm sounds which are merely representative of those which may be produced are all disclosed in detail in the aforementioned application. I

The matrix 23 includes OR circuits in which various ones of the output lines 24 and 24 are OR connected by diodes 36 to produce, on ORl output lines 37, the OR combination of one or more output lines 24 and 24. As indicated in matrix 23, certain additional combinations are achieved by AND connection of various input lines 22 to the auxiliary output lines 24 where the AND combinations of'lines 24' used in making up some of the OR configurations are not used individually in the AND outputs 27. Thus the combinations on OUT- PUT lines 24 and those on auxiliary output lines 24 may be OR connected to produce further versatility in the total available output combinations while at the same time minimizing the requirements for additional circuit components and connections. The OR outputs 37 are connected to corresponding inputs 38 on the selector switch 2S.

For the purpose of developing an automatic rhythm follow-up signal, an integrator 41 is provided which has two inputs; one, a pulse input 42 derived directly from pedal manual 33, and a square-wave input 43 derived from the ZERO output of the binary stage 17. The waveform on lead 43 has a transition from negative to positive at the time when a pedal manual actuation would ordinarily be imposed by the player on the pedal keyboard 43. By using this pedal actuation to pass the polarity of the ZERO output of binary stage 17 to the integration capacitor of integrator 41, a positive or negative increment can be applied to the integration capacitor, and thus the voltage level of the capacitor can be raised or lowered depending upon whether the actuation of the pedal manual 33 occurs during the negative or positive portion of the square-wave input on line 43.

This voltage level on the integration capacitor of integrator 41 is applied on line 44 to the frequency control input 12 of phase generator 11 when switch 45 is in the position shown. Thus, the frequency of pulse generator 11 will be controlled to maintain the square-wave transition of the wave on line 43 in synchronisrn with the actuation of the pedal manual 33 by the player as he plays the composition, and the automatic rhythm generation will, in fact, follow the tempo imposed by the player as he actuates the pedal keyboard 33.

In order to provide a predetermined and iixed tempo for the repetitive rhythm generated by the instrument, switch 45 may be actuated to terminal 46 which supplies a fixed but adjustable voltage to the frequency control input 12 by means of adjustment of slider 47 on potentiometer 48. The potentiometer 48 is connected to a suitable DC voltage to provide the desired range of frequency control for the pulse generator 11.

The operation of the arrangement of FIG. 1 will now be described withreference to FIG. 2V which shows the waveforms available from the counter chain 14 and Table I which shows the various counter-combinations which are used to generate various outputs for different rhythms and the associated rhythm sound producer which may be used. In Table I the simplest rhythm output is indicated as' being on line 1 where a pulse occurs for each ZERO count! on the scale-of-three counter' 15. As indicated in Table I, this pulse for the cha-cha-cha and rhumba would be passed through the brush rhythm instrument to simulate the sound of a brush on a snare drum for each ZERO count of the counter 15. Similarly, for example, output line 10 indicated in Table I produces an output pulse for the simultaneous occurrence the ONES output of counters' 17 and 18 and ZEROS output on the counters 16 and 15. The pulse which occurs for this combination of inputs is useful in the tango to actuate the rhythm instrument that simulates the sound of the cymbal as indicated for output 10 in Table I. It can be seen for the particular instrument of Table I, thirteen separate output lines are provided for generating the rhythm sequences indicated. These outputs numbered 1 13 in Table I are the lines represented by numeral 27 in FIG. 1. It should be understood that the numbered outputs l-13 in Table I have no relation to the corresponding numbers appearing on the drawing of FIG. 1.

Table II shows the derivation of the combinations numbered 14-30 in Table II. These combinations appear on lines 24 and are generated upon the coincidence of the signals for the various counter stages as indicated. These AND gate patterns of Table II are used only to generate the more complex rhythms, consisting of one or more AND gate patterns combined in the OR circuits which have their outputs in FIG. l on line 37. Here again the numerals 14 through 30 in Table II represent the number of distinct AND gate patterns utilized in a particular instrument and these numerals do not relate to the same numerals as used in the drawing FIG. l.

Table III shows a set of OR gate patterns achieved on the output lines A-R and appearing on the lines indicated 37 in FIG. 1. The various pulse patterns are achieved by the OR circuits combining the particular AND gate pattern indicated. For example, pattern A in Table III is achieved by combining in an OR circuit AND gate pattern 11 with AND gate pattern 8 both from Table I. Similarly, for example, OR gate pattern F is obtained by OR circuits which combine AND gate pattern 7 from Table I and AND gate pattern 19 from Table II.

From the foregoing considerations of Tables I, II, and III, it will be apparent that extremely complex and sophisticated rhythm sequences can be generated and the desired musical eect's produced by selecting portions of ythese rhylthm sequences into the various rhythm instruments in the combinations which achieve the desired artistic eect. Obviously, the specific examples given do not begin to exhaust the possibilities which an artist can achieve and which the manufacturer can provide by suitable switch selections and matrix connections, depending upon the degree of complexity which is desired for any particular instrument built in accordance with the invention.

FIG. 2 shows the timing waveforms generated by pulse generator 11 with the corresponding code designation for each pulse for two measures consisting of a total of 48 pulses. This is a frequency which is an integral multiple of the basic rhythm frequency of the instrument which may be set or imposed by the player, and, thus, two successive measures of the composition to be played are subdivided into 24 intervals each yequally spaced. In this manner, successive measures can have slight variations in the rhythm sequence, as required for certain compositions. The scale-of-three counter 15 has the three outputs, 0, l, and 2, shown in FIG. 2. The binaries 16, 17, 18, and 19 have the O and l outputs shown in the remaining waveforms of FIG. 2. By comparing the AND and OR combinations specified in Tables I, II, and III with the waveforms shown in FIG. 2, it can readily be determined which pulses are passed to the rhythm instruments 29 under any given conditions.

For achieving the automatic rhythm control provided by the loop which includes integrator 41, it can be seen in FIG. 2 that the ZERO output of binary stage 17 provides negative polarity just prior to the basic beat and the midway between the basic beat represented by pulses 24 and 4S and provides a positive waveform just after the occurrence of pulses 1, 12, 24, 36 and 48. This waveform is used to provide the proper polarities yfor increasing or decreasing the frequency of pulse generator 11 depending upon whether the pedal beat falls in the negative or positive portion of the ZERO output of binary waveform 17. If desired, further gating can be provided to make unambiguous the fact that the integrator error signal is derived only from the particular transitions of the ZERO waveform of binary 17.

TABLE I Counter Stage AND gate patterns, used in rhythms Cha-Cha-Cha & Rhumba (Blush).

Fox Trots II & IV & Shuttle (Drum),

Tango (Brush).

Beguine (Woodblock I II d'. Brush).

Marches, Fox Trots I da III. Tango, Samba, Rhumba (Drum), Cha-Cha (Torn Tom I), Metronome (WB II), Fox Trot I & II (Brush), Fox Trot III & IV (Cymbal).

Fox Trot I d: II (Cymbal).

Western (Woodblock Il).

Western, Waltzes, Beguine (Drum), Marches, Waltzes, Tango, Samba (Tom Tom II), Western (Woodblock Waltz I (Cymbal).

Waltz I (Brush), Waltz II (Cymbal). Tango (Cymbal).

Cha-Cha-Cha (Tom Tom II). Western (Woodblock III).

Rhumba (Woodblock II).

OHP-l OQO or# Ol @roo oo oo TABLE II [AND gate patterns used only with OR gates] Counter Stage Counter Stage Lines 24 TABLE III Outputs 1-30 From Waltz II (Brush).

Fox Trots III & IV (Brush).

Tango (Tom Tom Il), Beguine (Tom Tom I).

Bolero (Drum).

Cha-Cha-Cha (Woodblocks I & II).

Rhumba (Tom Tom I).

Rhumba (Tom Torn II).

6/8 March (Tom Tom II Brush).

Rhumba (Woodblock I).

Shuttle (Brush).

Samba (Tom Tom II).

Samba (Woodblock I).

Samba (Brush).

Rhumbadz Samba (Clave).

Bolero (Tom Torn II).

Cha-ChafCha (Clave).

Tango (Woodblock I & Clave) 2/4 March (Tom Tom II & Brush).

Obviously, many modifications can be made by those skilled in the art in practicing the invention herein disclosed, and the invention is accordingly to be limited only by the scope of the appended claims.

-I claim:

Ll. An electronic musical instrument for genera-ting continuous repetitive rhythm patterns comprising a repetitive pulse generator having a frequency corresponding to a multiple of the basic rhythm frequency for said instrument, a multistage frequency divider coupled to said generator for couting down submultiples of the frequency of said generator, a matrix connected to the stages of said frequency divider and .to said pulse generator for producing a plurality of outputs each consisting of a diierent predetermined combination of pulses from said generator, and means for selectively coupling different ones of said outputs to energize rhythm ci-rcuits with `the combinations of pulses on the selected outputs.

2. Apparatus according to claim 1 and including means for adjusting the frequency of said pulse generato-r.

3. An electronic musical instrument for generating continuous repetitive rhythm patterns comprising a repetitive pulse generator having a signal controlled frequency range corresponding `to a multiple `of the basic rhythm frequency range for said instrument, a multistage frequency divider coupled to said generator for counting down submu-ltiples of the frequency of said generator, a matrix connected to the stages of ysa-id frequency divider and to said pulse generator for producing a plurality of outputs each consisting of a different predetermined combination of pulses from said generator, and means for selectively coupling different ones of said outputs to energize rhythm circuits with the combinations of pulses on .the selected outputs, and means for applying a vari-able frequency control sig- -nal to said repetitive pulse generator.

`4. Apparatus according to claim 3 and including means for manually adjusting the frequency of said pulse generator.

5. Apparatus according to claim 3 and including associated instrument tempo signal input mean-s and means for automatically controlling said frequency control signal in accordance with the tempo of said associated instrument.

6. Apparatus according to claim 3 and including associated instrument tempo signal input means and means for selectively manually adjusting or automatically controlling said frequency control signal in accordance with the tempo of said associated instrument.

7. Apparatus according to cla-im 3 and including means for coupling lfrom said divider a wave having polarity transitions at the rhythm beat for said basic rhythm frequency, means for transferring said wave to a contro1signal circuit in tempo with the rhythm beat imposed by a player-operated instrument, and storage means associated with said cont-rol signal circuit and responsive to the polarity of said wave at the time of transfer for producing said variable frequency control signal to conform the rhythm beat of said generato-r to the rhythm beat imposed by said player.

8. Apparatus according t-o claim '3 in which said fre-v quency divider comprises a scale-of-three counter coupled to said generator and a plural stage binary counter coupled to said scale-ofthree counter.

9. Apparatus accord-ing to claim 3 in which said divider has count terminals respectively providing said subrnultiples and said matrix comprises a plurality of separate input lines coupled respectively to said count terminals of said divider, a plurality of separate output lines for supplying said outputs, first means for providing AND connections from said pulse generato-r to each of said output lines, and second means providing AND connections from different combinations of said input lines to each of said output lines for energizing `said output lines With only p-redetermined combinations of pulses from said pulse generator.

10. Apparatus according to claim `9 in which said second means providing AND connections between said Iinput and output lines comp-rises a diode Ifor each connection.

11. Apparatus according to claim y9 in which said output lines include auxiliary output lines and means providing O-R connections from auxiliary output lines to other output lines thereby providing on said auxiliary output lines combinations of pulses `on said other output lines.

ARTHUR GAUSS, Primary Examiner.

Z. ZAZWORSKY, Assistant Examiner. 

1. AN ELECTRONIC MUSICAL INSTRUMENT FOR GENERATING CONTINUOUS REPETITIVE RHYTHM PATTERNS COMPRISING A REPETITIVE PULSE GENERATOR HAVING A FREQUENCY CORRESPONDING TO A MULTIPLE OF THE BASIC RHYTHM FREQUENCY FOR SAID INSTRUMENT, A MULTISTAGE FREQUENCY DIVIDER COUPLED TO SAID GENERATOR FOR COUNTING DOWN SUBMULTIPLES OF THE FREQUENCY OF SAID GENERATOR, A MATRIX CONNECTED TO THE STAGES OF SAID FREQUENCY DIVIDER AND TO SAID PULSE GENERATOR FOR PRODUCING A PLURALITY OF OUTPUTS EACH CONSISTING OF A DIFFERENT PREDETERMINED COMBINATION OF PULSES FROM SAID GENERATOR, AND MEANS FOR SELECTIVELY COUPLING DIFFERENT ONES OF SAID OUTPUTS TO ENERGIZE RHYTHMS CIRCUITS WITH THE COMBINATIONS OF PULSES ON THE SELECTED OUTPUTS. 